1) Field of the Invention
The present invention relates generally to agricultural earthworking implements, and, more specifically, to a wear shin for an implement such as a deep tillage ripper.
2) Related Art
Many different forms of conservation tillage practices are emerging which involve leaving plant residue on the surface of the ground to preserve top soil. In one of these forms, referred to as strip tillage, a strip of soil where crop will be planted is tilled and crop residue or a cover crop is left between the tilled strips. Typically, strip till machines utilize a combination of fluted coulters to help till the soil and a rolling basket to break clods. Strip tillage is often combined with a toolbar mounted ripper or subsoiler to break through compacted layers of soil, and the coulters are angled to throw soil inwardly over the slot formed by the ripper. The coulters in some machines are mounted on a simple swing arm which floats vertically.
The ripper or subsoiler tool typically includes an upright shank having a relatively narrow profile with a lower end supporting a deep tillage point or tooth. The leading edge of the shank is subject to very high wear forces from soil and trash flow as the implement moves forwardly through the soil. To reduce shank wear and damage, and to avoid costly and time consuming shank replacements, protective wear shins often are provided for the leading edge of the shank. With use, the shins wear down and then must be replaced. Wear life of the shins often is less than desired, particularly when the implement is operating in hard or highly abrasive soils. In addition, a typical wear shin can substantially increase ripper penetration and draft loads and result in need for a higher horsepower tractor for a given number of ripper tools. Some available shins and shin attaching structures present forward trash and soil contacting profile that is substantially increased over that of the shank alone. Most have planar type angled profiles that are inefficient for slicing and penetrating the soil and for moving trash and soil towards the sides of the shank.